1. Technical Field
Present invention embodiments relate to archiving data, and more specifically, to archiving data in a database management system employing an accelerator system. Present invention embodiments involve transparent and online access to the archived data through the database management system.
2. Discussion of the Related Art
Managing data volume in an enterprise data warehouse (DWH) has become a major factor for data warehouse design. Managing and querying numerous rows of table data adversely impacts the data warehouse in several manners. For example, disk space is required to store the voluminous amounts of data which may be expensive, especially for high-quality storage (e.g., IBM z/OS storage servers). The size of indexes within a database management system (DBMS) for the data warehouse is increased due to the high number of table rows to be indexed. This further leads to slower index access due to the index size. Since indexes are typically implemented as B-Tree data structures, the index size directly influences the height of the B-Tree. Further, a buffer pool is less efficient since more data has to be handled. This requires more memory to maintain the I/O reduction attained by use of the buffer pool. In addition, maintenance operations (e.g., back-up and recovery) are slower due to increased amounts of data.
Although reducing the sheer data volume in a data warehouse tends to alleviate the above adverse impacts, this approach may impede access to removed data and/or require modification of existing mechanisms or applications to access the removed data.